body, body * {
  margin: 0;
  padding: 0;
}
button {
  border: none;
  background-color: transparent;
}
header {
  height: 64px;
}
.content_top {
  padding: 40px 0 60px;
  text-align: center;
  background-color: #454d64;
}
.content_top h3 {
  margin: 0px 0 8px;
  padding-top: 30px;
  font-size: 46px;
  font-weight: 600;
  height: 56px;
  line-height: 56px;
  color: #fff;
}
.content_top .desc {
  margin-top: 0;
  font-size: 16px;
  color: #fff;
}
.content_top .learn {
  display: inline-block;
  margin-top: 20px;
  padding: 8px 0;
  background: #4569d4;
  border: 1px solid #4569d4;
  border-radius: 22px;
  box-sizing: border-box;
  cursor: pointer;
  outline: none;
  transition: all .3s;
}
.content_top .learn :hover {
  opacity: .8;
}
.content_top .learn button {
  font-size: 16px;
  color: #fff;
  padding: 0 32px;
}
.content{
  margin: 50px auto 0;
  width: 1100px;
  display: flex;
  justify-content: space-between;
}
.content .item {
  width: 300px;
  text-align: center;
}
.content .item h5 {
  margin-bottom: 12px;
  font-size: 20px;
  line-height: 1;
  color: #454d64;
}
.content h5 img {
  width: 50px;
}
.content .item p {
  color: #717484;
  font-size: 14px;
  line-height: 22px;
}
.code {
  display: flex;
  width: 80%;
  margin: 30px auto 80px;
  padding-top: 30px;
  text-align: center;
  justify-content: space-between;
  border-top: 1px solid #ccc;
}
.code .text {
  margin-right: 20px;
}
.code .text h3 {
  margin-bottom: 20px;
  color: #282c34;
}
.code .text p {
  font-size: 17px;
  line-height: 1.8;
  text-align: left;
}
.code img {
  width: 70%;
  border-radius: 5px;
}
.footer {
  width: 100%;
  padding: 10px 0;
  position: fixed;
  bottom: 0;
  background-color: #454d64;
  text-align: center;
  color: #fff;
}